Walter Josef Fischer—known here in Hamburg, Germany, as OZ—was a fucking legend, even if most people could never pick him out of a crowd. Aged and slow with a worn, creased face and a hunch, he walked unseen with me through Hamburg as he painted walls and swore at trains. And yet, with his spray can, he’d changed the face of this city.

Up until his death last Thursday, the 64-year-old left his tag—a simple smiley face—hundreds of thousands times on local walls, sidewalks, roofs and lampposts.

Vocativ got a last glimpse into the world of Germany’s legendary, inscrutable OZ before his death last Thursday